Steam-shovel-operating mechanism.



F. W. SCHMITHALS.

STEAM SHOVEL OPERATING MECHANISM.

APPLICATION HLED JULY 11,19.

Patented Dec. 3, 1918.

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FREDERICK W. SCHMITHALS, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO BUCYlEt'US COMPANY, OI SOUTH MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

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Specification of Letters Patent.

Patented Dec. 3, ISIS.

Application filed July 11, 1917. Serial No. 179,813.

To all whom it may concern:

Be it known that I, FREDERICK- W. SCHMITHALS, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in Steam-Shovel-Operating Mechanism, of which the following is a specification.

-My invention relates to means for operating and controlling boom engines for steam shovels and the like. I have illustrated a part of a steam shovel showing the boom the forward end of the car body upon which the boom is pivoted and the thrusting engines on the boom. The other parts are not needed in order to make my invention clear and I have, therefore, omitted them.

It will be understood that the operator ordinarily stands upon the car to control the hoisting and swinging engines which form an essential part of the apparatus it self but which are not here illustrated and that another operator usually is placed upon the boom to control the thrusting engines in cooperation with the operator on the car, that is two operators under ordinary circumstances are needed to cooperate to control the engine. My invention is adapted to do away with the need of the second operator and it deals specifically with means for enabling the one operator from a station on the car to control both the swinging and hoisting engines and the thrusting engines on the boom. This makes it possible to arrange the controls coordinately so that one man may control them. all and so that the human equation is reduced to its least possible minimum.

My invention is illustrated more or less diagrammatically in the accompanying drawings wherein- Figure 1 represents detailed diagrammatic side elevation of the forward portion of a steam shovel car and fragment of the boom pivoted thereon;

Fig. 2 is a detaileddiagrarnmatic plan view of a part of the boom with the thrusting engines mounted thereon and showing the connecting mechanisms the boom being here shown in'its central position,

lFig. 3 is a partial plan view similar to Fig. 2 with. the boom swung to one side;

Fig. t is a detailed side elevation of a modihed form.

7 length.

Like parts are indicated by like characters in the drawings:

A represents a car body or other platform.

B represents a swinging boom, swinging about a vertical axis XX, and mounted upon swing circle C, which revolves upon a pintle attached to the car body. 18 is the thrusting engine, which is controlled as to speed, and reversed, by means of a distribution valve not shown, but which is operated by the valve stem B through a shaft and bell cranks B reach rod B and lever B, keyed upon-shaft B. Shaft B is supported by two bearings B located on opposite sides of the boom structure, and between these two bearings are keyed to the shaft B the two levers 13", extending preferably when in central position in aihorizontal direction. Directly above the two levers 1B are two extending arms of a bent strap B, which is fulcrumed upon the transverse bolt B.

The bolt B is vertically above the shaft B and the two projecting arms of the bent strap B are located directly above the two pro ect1n% ach lever B is connected to the corresponding arm of strap B, which is v vertically above it, by a bar B. The two vertlcal bars B are therefore widely separated as shown, and a single U-shaped strap 13 having its closed end bent to a semicircular form, is rigidly secured to the two arms B, being in effect integral therewith.

The center of curvature of strap 1B is located on the vertical axis XX of the swing circle C, about which axis the boom revolves. The swing circle and base plate thereunder are formed with a large opening through which passes the hoisting chain 13. This chain must be free to operate in any position of theboom, and it is obvious that the above described construction of the bent strap B leaves an opening through which the chain may freely pass.

The semi-circular gaged by one arm 0* the bell crank C, the other arm being connected by a reach rod C to the operating lever C. It may be necessary to regulate the speed or direction of the thrusting engine B upon the boom in any swinging position of the boom. The

art of strap B is en levers B and are of the same boom swings through a total angle of about tral position parallel to the car-body and also swung through an angle of 45, that the semi-circular portion of strap B en gages the jaw in bell crank C irrespective of the angular position of the boom. This is because the rotation of the platform carrying the boom merely causes the semi-circular loop to slide along between the jaws on the end of the bell crank lever without interfering with the connection between them.

In the modified form shown in Fig. i the bell crank lever B is slotted as at D and slidably engages a pin'D in the sliding bar D which bar isfree to slide in the bearings -D B 1) is a similar semi-circular strap extending rearwardly from .two such bars D and curved about the axis of rotation of the member C so as to be concentric therewith. This strap D rotates within the jaws of the bell crank lever C.

The use and operation of my invention are as follows Referring first to the preferred form shown in Fig: 1, I have indicated the arcs through which the ends of the bell crank levers B and links B travel in dotted lines as indicated. Since the lines joining the pivot points of each end of these levers are parallel, the levers will have a parallel movement and the members B will move up and point in a horizontal plane. The curved member being mounted on the boom support will rotate with it and this curved mem-' her will travel back and forth through the jaws of the bell crank lever and will be in operative engagement with such jaws no matter what the position of the turn table upon which the boom is mounted.

Therefore, any movement of the lever C will result in a proportional movement of the throttle valve stem B no matter what the position of the boom at the time the movement was made, also, subsequent swinging of the boom after a given adjustment of the throttle lever stem is accomplished will not change that adjustment and thereby cause movements of the thrusting engine which were not intended.

itaeaaee In the modified form shown in Fig. 4, the situation is exactly the same except that the parallel movement is provided by means of the sliding bar which is held in a permanent vertical position by the guide bearings therefor. There may be one or more of these bars and the curved segment strip will be mounted upon them in the usual manner as shown, the operation being exactly the same as in connection with the preferred form shown in Fig. 1.

I claim 1. In a steam shovel, a working platform, a swinging boom machinery mounted on th boom, an operating mechanism for controlling the boom machinery from the car body, an extension therefrom concentric with the axis of rotation of the boom, a lever in operative engagement with such arcuate member and means for maintaining such arcuate member in position in a plane normal to such axis of rotation comprising a plurality of links, a base upon which they are pivoted, an arm supported by them and carrying such arcuate member.

2. The combination with a workin platform of a swinging beam mounted tiereon and working mechanism on the beam of an operating lever, connection between such working mechanism and the operating lever comprising two separate cooperating members one member being a lever mounted on the platform with a fork end which loosely engages the other member, the other being an arcuate member concentric with the axis of rotation of the beam, said member being rigidly mounted on a rocking member parallel to the axis of rotation of the beam, a lever controlled by said rocking member having pivoted to its free end a shaft controlling the working mechanism.

In testimony whereof, I ailix my signature in the presence of two witnesses this 22nd day of June, 1917.

FREDERICK W. SCHMITHALS.

Witnesses:

KATHRYN OCONNELL, Rom. M. Rumors. 

